Development of invasive bladder cancer is a definite risk in patients with flat carcinoma in situ (CIS) associated with multifocal concurrent superficial papillary tumors. In a prior prospective randomized trial, the authors showed that intravesical BCG reduces local tumor recurrences and prolongs the disease free interval in patients with recurrent, papillary bladder tumors treated by transurethral resection (TUR) and/or fulguration. In this study, BCG was administered intravesically, 120 mg in 50 ml saline and percutaneously, 5 × 107 viable organisms, weekly for 6 weeks. The current study was conducted to determine the impact of this regimen in patients with flat in situ carcinoma. Of the first 69 patients entered, 41 (59%) had multiple (2) lesions of flat CIS associated with papillary tumors: 17/34 (50%) in the TUR + BCG group and 24/35 (69%) in the TUR alone group. Complete regression of CIS documented by negative bladder biopsy and negative urine cytology results was seen in 11/17 (65%) of the BCG treated patients for a median duration of 18 months (range, 12–30 months) and in 2/24 (8%) patients in the TUR alone group for a median duration of 3 months (P < 0.01). In situ carcinoma failed to respond to intravesical BCG in seven patients, three of whom required cystectomy for local progression of disease. In two of these three patients, cystectomy was performed for CIS involving the prostatic ducts and no tumor was found in the bladder specimen. This suggested that the response of in situ cancer required that the epithelium be adequately exposed to BCG, and that intravesical BCG + TUR may potentially reverse the insidious natural history of carcinoma in situ compared with a control group treated with endoscopic destruction alone.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/1097-0142%2819830401%2951%3A7%3C1323%3A%3AAID-CNCR2820510724%3E3.0.CO%3B2-2

Effect of intravesical Bacillus Calmette-Guerin (BCG) on carcinoma in situ of the bladder.

Dietary administration of sodium saccharin to male Fischer rats increased the rate of DNA synthesis of the urinary bladder epithelium as measured by tritiated thymidine uptake. A multifocal mild epithelial hyperplasia was induced, which was most readily detected by scanning electron microscopy, with pleomorphic microvilli present on many of the hyperplastic cells.

https://cancerres.aacrjournals.org/content/canres/40/3/734.full.pdf

Saccharin-induced Hyperplasia of the Rat Urinary Bladder

To analyze the implications for human health, the toxicologist requires four sets of data: the results of toxicity and other studies in animals; quantitative data on actual or potential human exposure; whatever information is available on effects of exposure in man; and the statistical extrapolations from the dose-response relationships in animals to the (usually) much lower levels of human exposure. Professional expertise in toxicology is essential to assess the nature and severity of the toxic effects observed in animals, including such characteristics as potential for progression, irreversibility and production of incapacity. Given sufficient data, an estimate can be arrived at of the likelihood that such effects will be elicited in human populations of differing susceptibilities. The criteria by which the overall implications for human health can be judged comprise both the direct effects on man, as well as the indirect consequences stemming from environmental impacts.

Implications for human health.

Urinary bladder damage caused by surgical incision, freeze-ulceration, or formalin instillation in male Fischer 344 rats was studied by light and scanning electron microscopy. The first two methods resulted in focal ulceration of the urinary bladder; the last induced diffuse mucosal damage. With each method, the damage was followed by regenerative hyperplasia and repair, the bladder mucosa returning to normal in 3-4 weeks. Epithelial cells in the hyperplastic areas had ropy microridges and uniform short microvilli on their luminal surfaces as observed by scanning electron microscopy. When the hyperplasia was marked, with nodular and papillary formation, occasional epithelial cells had pleomorphic microvilli on their surfaces. Rats treated either by surgical incision or freeze-ulceration had normal bladders after a 2-year observation period. Combined with results from previous experiments, pleomorphic microvilli are not a marker of neoplasia or irreversibility but appear with marked or prolonged mucosal proliferation even if reversible.

Scanning electron microscopic examination of reversible hyperplasia of the rat urinary bladder.

Follow‐up of Patients with “Superficial” Transitional Cell Carcinoma of the Bladder: the Case for a Change in Policy

Carcinoma of the urinary bladder appears to arise, in at least some cases, from carcinoma in situ developing in a field of atypical epithelial proliferation. There is both a spatial and temporal relationship between invasive and in situ bladder cancer, although the exact relationship between the noninvasive flat and papillary types of tumors is not known. Prenoeplastic bladder lesions are defined as irreversible, although not necessarily progressive, and an experimental animal model of the disease has been developed. The appearance of pleomorphic microvilli on the luminal surface of epithelial cells of the urinary bladders of Fischer rats is correlated with the irreversibility of hyperplastic epithelial lesions induced by feeding N-[4-(5-nitro-2-furyl)-2-thiazolyl] formamide (FANFT) to the test animals. This alteration can be visualized by scanning electron microscopy of cytologic and histologic preparations.

The pathogenesis of bladder cancer.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

G. K. Nagy

Author Tools

Chat about Author

Papers

The pathogenesis of bladder cancer.